1. Technical Field
The present invention relates to a fluid container that is used as an ink cartridge in an inkjet printer, for example.
2. Related Art
Ink cartridges for inkjet printers may have a storage unit for ink sacks that hold fluid ink for supply to the print head, and a waste ink recovery unit containing a waste ink sponge that absorbs waste ink fluid discharged from the inkjet print head, disposed inside an ink cartridge case as taught in Japanese Patent No. 3533897 and Japanese Unexamined Patent Appl. Pub. JP-A-2001-353882. Ink cartridges that have a waste ink sack inside the cartridge case instead of a waste ink sponge are also described in Japanese Unexamined Patent Appl. Pub. JP-A-2002-307705 and Japanese Unexamined Patent Appl. Pub. JP-A-2002-307720, for example.
When an ink cartridge is loaded into the ink cartridge loading unit of the inkjet printer, an ink supply path formation member and waste ink recovery path formation member disposed on the ink cartridge loading unit side are inserted to an ink supply port and a waste ink recovery port formed in the cartridge case so that ink can be supplied from the ink cartridge and waste ink can be recovered from the inkjet printer. For example, an ink supply needle and a waste ink recovery needle disposed on the ink cartridge loading unit side respectively push open an ink supply needle insertion port and a waste ink recovery needle insertion port formed in the cartridge case and are inserted to the ink sack and waste ink recovery unit so that ink can be supplied and waste ink can be recovered.
With this type of ink cartridge, however, the main container can preferably be disassembled and the ink supply sack and waste ink recovery member replaced with new ones when the ink supply is depleted or the waste ink recovery unit becomes filled with waste ink so that the main container can then be reassembled and reused to conserve resources.
So that the main container of an ink cartridge or other fluid container can be disassembled and then reassembled, the main container may be rendered from a plurality of container forming members that are assembled and held together by a locking mechanism that can hold and release the container forming members. One such locking mechanism known from the literature has at least one protruding tab or latch formed on one container forming member that rides over while elastically deforming a matching hook or catch formed on another container forming member so that the latch and hook engage when the hooks elastically return to the original position. To disengage this connection, the hooks are elastically deformed by force and separated from the latches.
To facilitate disassembly and reassembly of the main container in a fluid container having a main container assembled by connecting a plurality of container forming members together by means of such a locking mechanism, the length of the hook (lance) may be increased for greater flexibility, or the engagement of the hook and latch may be reduced so that the hooks can be easily disengaged from the latches. However, because such methods weaken the engagement force of the locking mechanism, the locking mechanism can be easily disengaged by the force of impact of being dropped, for example, and the main container may be easily broken. Conversely, if the length of the lance (hook) is shortened or the amount of engagement is increased, disassembly and reassembly of the main container becomes more difficult. In addition, because great force is required to release the engagement, stress is concentrated at the base of the hook, for example, and when the main container is made of plastic, the engaging parts may be plastically deformed, stress whitened (blushing), and embrittled.